Is there an end to space?

I have always wondered if i got on a spaceship with infinity gas and wandered into the universe will i ever stop is there a wall or some force that i cant keep going no more? whats outside of that? My mind thinks crazy but what if this so called universe with all the galaxies inside it were trapped inside a jar sitting on some really gigantic reptile type creatures bookshelf? and those realy gigantic reptile creatures were microscopic atoms to some other greater beings beyond our imaginations.